CompilerInstance.cpp revision 1ec4a86a867fc04f35d13bc9e33b04cf2171fe41 
1//===--- CompilerInstance.cpp ---------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include "clang/Frontend/CompilerInstance.h"
11#include "clang/AST/ASTConsumer.h"
12#include "clang/AST/ASTContext.h"
13#include "clang/AST/Decl.h"
14#include "clang/Basic/Diagnostic.h"
15#include "clang/Basic/FileManager.h"
16#include "clang/Basic/SourceManager.h"
17#include "clang/Basic/TargetInfo.h"
18#include "clang/Basic/Version.h"
19#include "clang/Frontend/ChainedDiagnosticConsumer.h"
20#include "clang/Frontend/FrontendAction.h"
21#include "clang/Frontend/FrontendActions.h"
22#include "clang/Frontend/FrontendDiagnostic.h"
23#include "clang/Frontend/LogDiagnosticPrinter.h"
24#include "clang/Frontend/SerializedDiagnosticPrinter.h"
25#include "clang/Frontend/TextDiagnosticPrinter.h"
26#include "clang/Frontend/Utils.h"
27#include "clang/Frontend/VerifyDiagnosticConsumer.h"
28#include "clang/Lex/HeaderSearch.h"
29#include "clang/Lex/PTHManager.h"
30#include "clang/Lex/Preprocessor.h"
31#include "clang/Sema/CodeCompleteConsumer.h"
32#include "clang/Sema/Sema.h"
33#include "clang/Serialization/ASTReader.h"
34#include "llvm/ADT/Statistic.h"
35#include "llvm/Config/config.h"
36#include "llvm/Support/CrashRecoveryContext.h"
37#include "llvm/Support/FileSystem.h"
38#include "llvm/Support/Host.h"
39#include "llvm/Support/LockFileManager.h"
40#include "llvm/Support/MemoryBuffer.h"
41#include "llvm/Support/Path.h"
42#include "llvm/Support/Program.h"
43#include "llvm/Support/Signals.h"
44#include "llvm/Support/Timer.h"
45#include "llvm/Support/raw_ostream.h"
46#include "llvm/Support/system_error.h"
47#include <sys/stat.h>
48#include <time.h>
49
50using namespace clang;
51
52CompilerInstance::CompilerInstance()
53  : Invocation(new CompilerInvocation()), ModuleManager(0),
54    BuildGlobalModuleIndex(false), ModuleBuildFailed(false) {
55}
56
57CompilerInstance::~CompilerInstance() {
58  assert(OutputFiles.empty() && "Still output files in flight?");
59}
60
61void CompilerInstance::setInvocation(CompilerInvocation *Value) {
62  Invocation = Value;
63}
64
65bool CompilerInstance::shouldBuildGlobalModuleIndex() const {
66  return (BuildGlobalModuleIndex ||
67          (ModuleManager && ModuleManager->isGlobalIndexUnavailable() &&
68           getFrontendOpts().GenerateGlobalModuleIndex)) &&
69         !ModuleBuildFailed;
70}
71
72void CompilerInstance::setDiagnostics(DiagnosticsEngine *Value) {
73  Diagnostics = Value;
74}
75
76void CompilerInstance::setTarget(TargetInfo *Value) {
77  Target = Value;
78}
79
80void CompilerInstance::setFileManager(FileManager *Value) {
81  FileMgr = Value;
82}
83
84void CompilerInstance::setSourceManager(SourceManager *Value) {
85  SourceMgr = Value;
86}
87
88void CompilerInstance::setPreprocessor(Preprocessor *Value) { PP = Value; }
89
90void CompilerInstance::setASTContext(ASTContext *Value) { Context = Value; }
91
92void CompilerInstance::setSema(Sema *S) {
93  TheSema.reset(S);
94}
95
96void CompilerInstance::setASTConsumer(ASTConsumer *Value) {
97  Consumer.reset(Value);
98}
99
100void CompilerInstance::setCodeCompletionConsumer(CodeCompleteConsumer *Value) {
101  CompletionConsumer.reset(Value);
102}
103
104// Diagnostics
105static void SetUpDiagnosticLog(DiagnosticOptions *DiagOpts,
106                               const CodeGenOptions *CodeGenOpts,
107                               DiagnosticsEngine &Diags) {
108  std::string ErrorInfo;
109  bool OwnsStream = false;
110  raw_ostream *OS = &llvm::errs();
111  if (DiagOpts->DiagnosticLogFile != "-") {
112    // Create the output stream.
113    llvm::raw_fd_ostream *FileOS(
114      new llvm::raw_fd_ostream(DiagOpts->DiagnosticLogFile.c_str(),
115                               ErrorInfo, llvm::raw_fd_ostream::F_Append));
116    if (!ErrorInfo.empty()) {
117      Diags.Report(diag::warn_fe_cc_log_diagnostics_failure)
118        << DiagOpts->DiagnosticLogFile << ErrorInfo;
119    } else {
120      FileOS->SetUnbuffered();
121      FileOS->SetUseAtomicWrites(true);
122      OS = FileOS;
123      OwnsStream = true;
124    }
125  }
126
127  // Chain in the diagnostic client which will log the diagnostics.
128  LogDiagnosticPrinter *Logger = new LogDiagnosticPrinter(*OS, DiagOpts,
129                                                          OwnsStream);
130  if (CodeGenOpts)
131    Logger->setDwarfDebugFlags(CodeGenOpts->DwarfDebugFlags);
132  Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(), Logger));
133}
134
135static void SetupSerializedDiagnostics(DiagnosticOptions *DiagOpts,
136                                       DiagnosticsEngine &Diags,
137                                       StringRef OutputFile) {
138  std::string ErrorInfo;
139  OwningPtr<llvm::raw_fd_ostream> OS;
140  OS.reset(new llvm::raw_fd_ostream(OutputFile.str().c_str(), ErrorInfo,
141                                    llvm::raw_fd_ostream::F_Binary));
142
143  if (!ErrorInfo.empty()) {
144    Diags.Report(diag::warn_fe_serialized_diag_failure)
145      << OutputFile << ErrorInfo;
146    return;
147  }
148
149  DiagnosticConsumer *SerializedConsumer =
150    clang::serialized_diags::create(OS.take(), DiagOpts);
151
152
153  Diags.setClient(new ChainedDiagnosticConsumer(Diags.takeClient(),
154                                                SerializedConsumer));
155}
156
157void CompilerInstance::createDiagnostics(DiagnosticConsumer *Client,
158                                         bool ShouldOwnClient) {
159  Diagnostics = createDiagnostics(&getDiagnosticOpts(), Client,
160                                  ShouldOwnClient, &getCodeGenOpts());
161}
162
163IntrusiveRefCntPtr<DiagnosticsEngine>
164CompilerInstance::createDiagnostics(DiagnosticOptions *Opts,
165                                    DiagnosticConsumer *Client,
166                                    bool ShouldOwnClient,
167                                    const CodeGenOptions *CodeGenOpts) {
168  IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
169  IntrusiveRefCntPtr<DiagnosticsEngine>
170      Diags(new DiagnosticsEngine(DiagID, Opts));
171
172  // Create the diagnostic client for reporting errors or for
173  // implementing -verify.
174  if (Client) {
175    Diags->setClient(Client, ShouldOwnClient);
176  } else
177    Diags->setClient(new TextDiagnosticPrinter(llvm::errs(), Opts));
178
179  // Chain in -verify checker, if requested.
180  if (Opts->VerifyDiagnostics)
181    Diags->setClient(new VerifyDiagnosticConsumer(*Diags));
182
183  // Chain in -diagnostic-log-file dumper, if requested.
184  if (!Opts->DiagnosticLogFile.empty())
185    SetUpDiagnosticLog(Opts, CodeGenOpts, *Diags);
186
187  if (!Opts->DiagnosticSerializationFile.empty())
188    SetupSerializedDiagnostics(Opts, *Diags,
189                               Opts->DiagnosticSerializationFile);
190
191  // Configure our handling of diagnostics.
192  ProcessWarningOptions(*Diags, *Opts);
193
194  return Diags;
195}
196
197// File Manager
198
199void CompilerInstance::createFileManager() {
200  FileMgr = new FileManager(getFileSystemOpts());
201}
202
203// Source Manager
204
205void CompilerInstance::createSourceManager(FileManager &FileMgr) {
206  SourceMgr = new SourceManager(getDiagnostics(), FileMgr);
207}
208
209// Preprocessor
210
211void CompilerInstance::createPreprocessor() {
212  const PreprocessorOptions &PPOpts = getPreprocessorOpts();
213
214  // Create a PTH manager if we are using some form of a token cache.
215  PTHManager *PTHMgr = 0;
216  if (!PPOpts.TokenCache.empty())
217    PTHMgr = PTHManager::Create(PPOpts.TokenCache, getDiagnostics());
218
219  // Create the Preprocessor.
220  HeaderSearch *HeaderInfo = new HeaderSearch(&getHeaderSearchOpts(),
221                                              getFileManager(),
222                                              getDiagnostics(),
223                                              getLangOpts(),
224                                              &getTarget());
225  PP = new Preprocessor(&getPreprocessorOpts(),
226                        getDiagnostics(), getLangOpts(), &getTarget(),
227                        getSourceManager(), *HeaderInfo, *this, PTHMgr,
228                        /*OwnsHeaderSearch=*/true);
229
230  // Note that this is different then passing PTHMgr to Preprocessor's ctor.
231  // That argument is used as the IdentifierInfoLookup argument to
232  // IdentifierTable's ctor.
233  if (PTHMgr) {
234    PTHMgr->setPreprocessor(&*PP);
235    PP->setPTHManager(PTHMgr);
236  }
237
238  if (PPOpts.DetailedRecord)
239    PP->createPreprocessingRecord();
240
241  InitializePreprocessor(*PP, PPOpts, getHeaderSearchOpts(), getFrontendOpts());
242
243  PP->setPreprocessedOutput(getPreprocessorOutputOpts().ShowCPP);
244
245  // Set up the module path, including the hash for the
246  // module-creation options.
247  SmallString<256> SpecificModuleCache(
248                           getHeaderSearchOpts().ModuleCachePath);
249  if (!getHeaderSearchOpts().DisableModuleHash)
250    llvm::sys::path::append(SpecificModuleCache,
251                            getInvocation().getModuleHash());
252  PP->getHeaderSearchInfo().setModuleCachePath(SpecificModuleCache);
253
254  // Handle generating dependencies, if requested.
255  const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
256  if (!DepOpts.OutputFile.empty())
257    AttachDependencyFileGen(*PP, DepOpts);
258  if (!DepOpts.DOTOutputFile.empty())
259    AttachDependencyGraphGen(*PP, DepOpts.DOTOutputFile,
260                             getHeaderSearchOpts().Sysroot);
261
262
263  // Handle generating header include information, if requested.
264  if (DepOpts.ShowHeaderIncludes)
265    AttachHeaderIncludeGen(*PP);
266  if (!DepOpts.HeaderIncludeOutputFile.empty()) {
267    StringRef OutputPath = DepOpts.HeaderIncludeOutputFile;
268    if (OutputPath == "-")
269      OutputPath = "";
270    AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/true, OutputPath,
271                           /*ShowDepth=*/false);
272  }
273}
274
275// ASTContext
276
277void CompilerInstance::createASTContext() {
278  Preprocessor &PP = getPreprocessor();
279  Context = new ASTContext(getLangOpts(), PP.getSourceManager(),
280                           &getTarget(), PP.getIdentifierTable(),
281                           PP.getSelectorTable(), PP.getBuiltinInfo(),
282                           /*size_reserve=*/ 0);
283}
284
285// ExternalASTSource
286
287void CompilerInstance::createPCHExternalASTSource(StringRef Path,
288                                                  bool DisablePCHValidation,
289                                                bool AllowPCHWithCompilerErrors,
290                                                 void *DeserializationListener){
291  OwningPtr<ExternalASTSource> Source;
292  bool Preamble = getPreprocessorOpts().PrecompiledPreambleBytes.first != 0;
293  Source.reset(createPCHExternalASTSource(Path, getHeaderSearchOpts().Sysroot,
294                                          DisablePCHValidation,
295                                          AllowPCHWithCompilerErrors,
296                                          getPreprocessor(), getASTContext(),
297                                          DeserializationListener,
298                                          Preamble,
299                                       getFrontendOpts().UseGlobalModuleIndex));
300  ModuleManager = static_cast<ASTReader*>(Source.get());
301  getASTContext().setExternalSource(Source);
302}
303
304ExternalASTSource *
305CompilerInstance::createPCHExternalASTSource(StringRef Path,
306                                             const std::string &Sysroot,
307                                             bool DisablePCHValidation,
308                                             bool AllowPCHWithCompilerErrors,
309                                             Preprocessor &PP,
310                                             ASTContext &Context,
311                                             void *DeserializationListener,
312                                             bool Preamble,
313                                             bool UseGlobalModuleIndex) {
314  OwningPtr<ASTReader> Reader;
315  Reader.reset(new ASTReader(PP, Context,
316                             Sysroot.empty() ? "" : Sysroot.c_str(),
317                             DisablePCHValidation,
318                             AllowPCHWithCompilerErrors,
319                             UseGlobalModuleIndex));
320
321  Reader->setDeserializationListener(
322            static_cast<ASTDeserializationListener *>(DeserializationListener));
323  switch (Reader->ReadAST(Path,
324                          Preamble ? serialization::MK_Preamble
325                                   : serialization::MK_PCH,
326                          SourceLocation(),
327                          ASTReader::ARR_None)) {
328  case ASTReader::Success:
329    // Set the predefines buffer as suggested by the PCH reader. Typically, the
330    // predefines buffer will be empty.
331    PP.setPredefines(Reader->getSuggestedPredefines());
332    return Reader.take();
333
334  case ASTReader::Failure:
335    // Unrecoverable failure: don't even try to process the input file.
336    break;
337
338  case ASTReader::Missing:
339  case ASTReader::OutOfDate:
340  case ASTReader::VersionMismatch:
341  case ASTReader::ConfigurationMismatch:
342  case ASTReader::HadErrors:
343    // No suitable PCH file could be found. Return an error.
344    break;
345  }
346
347  return 0;
348}
349
350// Code Completion
351
352static bool EnableCodeCompletion(Preprocessor &PP,
353                                 const std::string &Filename,
354                                 unsigned Line,
355                                 unsigned Column) {
356  // Tell the source manager to chop off the given file at a specific
357  // line and column.
358  const FileEntry *Entry = PP.getFileManager().getFile(Filename);
359  if (!Entry) {
360    PP.getDiagnostics().Report(diag::err_fe_invalid_code_complete_file)
361      << Filename;
362    return true;
363  }
364
365  // Truncate the named file at the given line/column.
366  PP.SetCodeCompletionPoint(Entry, Line, Column);
367  return false;
368}
369
370void CompilerInstance::createCodeCompletionConsumer() {
371  const ParsedSourceLocation &Loc = getFrontendOpts().CodeCompletionAt;
372  if (!CompletionConsumer) {
373    setCodeCompletionConsumer(
374      createCodeCompletionConsumer(getPreprocessor(),
375                                   Loc.FileName, Loc.Line, Loc.Column,
376                                   getFrontendOpts().CodeCompleteOpts,
377                                   llvm::outs()));
378    if (!CompletionConsumer)
379      return;
380  } else if (EnableCodeCompletion(getPreprocessor(), Loc.FileName,
381                                  Loc.Line, Loc.Column)) {
382    setCodeCompletionConsumer(0);
383    return;
384  }
385
386  if (CompletionConsumer->isOutputBinary() &&
387      llvm::sys::ChangeStdoutToBinary()) {
388    getPreprocessor().getDiagnostics().Report(diag::err_fe_stdout_binary);
389    setCodeCompletionConsumer(0);
390  }
391}
392
393void CompilerInstance::createFrontendTimer() {
394  FrontendTimer.reset(new llvm::Timer("Clang front-end timer"));
395}
396
397CodeCompleteConsumer *
398CompilerInstance::createCodeCompletionConsumer(Preprocessor &PP,
399                                               const std::string &Filename,
400                                               unsigned Line,
401                                               unsigned Column,
402                                               const CodeCompleteOptions &Opts,
403                                               raw_ostream &OS) {
404  if (EnableCodeCompletion(PP, Filename, Line, Column))
405    return 0;
406
407  // Set up the creation routine for code-completion.
408  return new PrintingCodeCompleteConsumer(Opts, OS);
409}
410
411void CompilerInstance::createSema(TranslationUnitKind TUKind,
412                                  CodeCompleteConsumer *CompletionConsumer) {
413  TheSema.reset(new Sema(getPreprocessor(), getASTContext(), getASTConsumer(),
414                         TUKind, CompletionConsumer));
415}
416
417// Output Files
418
419void CompilerInstance::addOutputFile(const OutputFile &OutFile) {
420  assert(OutFile.OS && "Attempt to add empty stream to output list!");
421  OutputFiles.push_back(OutFile);
422}
423
424void CompilerInstance::clearOutputFiles(bool EraseFiles) {
425  for (std::list<OutputFile>::iterator
426         it = OutputFiles.begin(), ie = OutputFiles.end(); it != ie; ++it) {
427    delete it->OS;
428    if (!it->TempFilename.empty()) {
429      if (EraseFiles) {
430        bool existed;
431        llvm::sys::fs::remove(it->TempFilename, existed);
432      } else {
433        SmallString<128> NewOutFile(it->Filename);
434
435        // If '-working-directory' was passed, the output filename should be
436        // relative to that.
437        FileMgr->FixupRelativePath(NewOutFile);
438        if (llvm::error_code ec = llvm::sys::fs::rename(it->TempFilename,
439                                                        NewOutFile.str())) {
440          getDiagnostics().Report(diag::err_unable_to_rename_temp)
441            << it->TempFilename << it->Filename << ec.message();
442
443          bool existed;
444          llvm::sys::fs::remove(it->TempFilename, existed);
445        }
446      }
447    } else if (!it->Filename.empty() && EraseFiles)
448      llvm::sys::fs::remove(it->Filename);
449
450  }
451  OutputFiles.clear();
452}
453
454llvm::raw_fd_ostream *
455CompilerInstance::createDefaultOutputFile(bool Binary,
456                                          StringRef InFile,
457                                          StringRef Extension) {
458  return createOutputFile(getFrontendOpts().OutputFile, Binary,
459                          /*RemoveFileOnSignal=*/true, InFile, Extension,
460                          /*UseTemporary=*/true);
461}
462
463llvm::raw_fd_ostream *
464CompilerInstance::createOutputFile(StringRef OutputPath,
465                                   bool Binary, bool RemoveFileOnSignal,
466                                   StringRef InFile,
467                                   StringRef Extension,
468                                   bool UseTemporary,
469                                   bool CreateMissingDirectories) {
470  std::string Error, OutputPathName, TempPathName;
471  llvm::raw_fd_ostream *OS = createOutputFile(OutputPath, Error, Binary,
472                                              RemoveFileOnSignal,
473                                              InFile, Extension,
474                                              UseTemporary,
475                                              CreateMissingDirectories,
476                                              &OutputPathName,
477                                              &TempPathName);
478  if (!OS) {
479    getDiagnostics().Report(diag::err_fe_unable_to_open_output)
480      << OutputPath << Error;
481    return 0;
482  }
483
484  // Add the output file -- but don't try to remove "-", since this means we are
485  // using stdin.
486  addOutputFile(OutputFile((OutputPathName != "-") ? OutputPathName : "",
487                TempPathName, OS));
488
489  return OS;
490}
491
492llvm::raw_fd_ostream *
493CompilerInstance::createOutputFile(StringRef OutputPath,
494                                   std::string &Error,
495                                   bool Binary,
496                                   bool RemoveFileOnSignal,
497                                   StringRef InFile,
498                                   StringRef Extension,
499                                   bool UseTemporary,
500                                   bool CreateMissingDirectories,
501                                   std::string *ResultPathName,
502                                   std::string *TempPathName) {
503  assert((!CreateMissingDirectories || UseTemporary) &&
504         "CreateMissingDirectories is only allowed when using temporary files");
505
506  std::string OutFile, TempFile;
507  if (!OutputPath.empty()) {
508    OutFile = OutputPath;
509  } else if (InFile == "-") {
510    OutFile = "-";
511  } else if (!Extension.empty()) {
512    SmallString<128> Path(InFile);
513    llvm::sys::path::replace_extension(Path, Extension);
514    OutFile = Path.str();
515  } else {
516    OutFile = "-";
517  }
518
519  OwningPtr<llvm::raw_fd_ostream> OS;
520  std::string OSFile;
521
522  if (UseTemporary) {
523    if (OutFile == "-")
524      UseTemporary = false;
525    else {
526      llvm::sys::fs::file_status Status;
527      llvm::sys::fs::status(OutputPath, Status);
528      if (llvm::sys::fs::exists(Status)) {
529        // Fail early if we can't write to the final destination.
530        if (!llvm::sys::fs::can_write(OutputPath))
531          return 0;
532
533        // Don't use a temporary if the output is a special file. This handles
534        // things like '-o /dev/null'
535        if (!llvm::sys::fs::is_regular_file(Status))
536          UseTemporary = false;
537      }
538    }
539  }
540
541  if (UseTemporary) {
542    // Create a temporary file.
543    SmallString<128> TempPath;
544    TempPath = OutFile;
545    TempPath += "-%%%%%%%%";
546    int fd;
547    llvm::error_code EC = llvm::sys::fs::unique_file(
548        TempPath.str(), fd, TempPath, /*makeAbsolute=*/ false, 0664);
549
550    if (CreateMissingDirectories &&
551        EC == llvm::errc::no_such_file_or_directory) {
552      StringRef Parent = llvm::sys::path::parent_path(OutputPath);
553      EC = llvm::sys::fs::create_directories(Parent);
554      if (!EC) {
555        EC = llvm::sys::fs::unique_file(TempPath.str(), fd, TempPath,
556                                        /*makeAbsolute=*/ false, 0664);
557      }
558    }
559
560    if (!EC) {
561      OS.reset(new llvm::raw_fd_ostream(fd, /*shouldClose=*/true));
562      OSFile = TempFile = TempPath.str();
563    }
564    // If we failed to create the temporary, fallback to writing to the file
565    // directly. This handles the corner case where we cannot write to the
566    // directory, but can write to the file.
567  }
568
569  if (!OS) {
570    OSFile = OutFile;
571    OS.reset(
572      new llvm::raw_fd_ostream(OSFile.c_str(), Error,
573                               (Binary ? llvm::raw_fd_ostream::F_Binary : 0)));
574    if (!Error.empty())
575      return 0;
576  }
577
578  // Make sure the out stream file gets removed if we crash.
579  if (RemoveFileOnSignal)
580    llvm::sys::RemoveFileOnSignal(OSFile);
581
582  if (ResultPathName)
583    *ResultPathName = OutFile;
584  if (TempPathName)
585    *TempPathName = TempFile;
586
587  return OS.take();
588}
589
590// Initialization Utilities
591
592bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input){
593  return InitializeSourceManager(Input, getDiagnostics(),
594                                 getFileManager(), getSourceManager(),
595                                 getFrontendOpts());
596}
597
598bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input,
599                                               DiagnosticsEngine &Diags,
600                                               FileManager &FileMgr,
601                                               SourceManager &SourceMgr,
602                                               const FrontendOptions &Opts) {
603  SrcMgr::CharacteristicKind
604    Kind = Input.isSystem() ? SrcMgr::C_System : SrcMgr::C_User;
605
606  if (Input.isBuffer()) {
607    SourceMgr.createMainFileIDForMemBuffer(Input.getBuffer(), Kind);
608    assert(!SourceMgr.getMainFileID().isInvalid() &&
609           "Couldn't establish MainFileID!");
610    return true;
611  }
612
613  StringRef InputFile = Input.getFile();
614
615  // Figure out where to get and map in the main file.
616  if (InputFile != "-") {
617    const FileEntry *File = FileMgr.getFile(InputFile);
618    if (!File) {
619      Diags.Report(diag::err_fe_error_reading) << InputFile;
620      return false;
621    }
622
623    // The natural SourceManager infrastructure can't currently handle named
624    // pipes, but we would at least like to accept them for the main
625    // file. Detect them here, read them with the more generic MemoryBuffer
626    // function, and simply override their contents as we do for STDIN.
627    if (File->isNamedPipe()) {
628      OwningPtr<llvm::MemoryBuffer> MB;
629      if (llvm::error_code ec = llvm::MemoryBuffer::getFile(InputFile, MB)) {
630        Diags.Report(diag::err_cannot_open_file) << InputFile << ec.message();
631        return false;
632      }
633
634      // Create a new virtual file that will have the correct size.
635      File = FileMgr.getVirtualFile(InputFile, MB->getBufferSize(), 0);
636      SourceMgr.overrideFileContents(File, MB.take());
637    }
638
639    SourceMgr.createMainFileID(File, Kind);
640  } else {
641    OwningPtr<llvm::MemoryBuffer> SB;
642    if (llvm::MemoryBuffer::getSTDIN(SB)) {
643      // FIXME: Give ec.message() in this diag.
644      Diags.Report(diag::err_fe_error_reading_stdin);
645      return false;
646    }
647    const FileEntry *File = FileMgr.getVirtualFile(SB->getBufferIdentifier(),
648                                                   SB->getBufferSize(), 0);
649    SourceMgr.createMainFileID(File, Kind);
650    SourceMgr.overrideFileContents(File, SB.take());
651  }
652
653  assert(!SourceMgr.getMainFileID().isInvalid() &&
654         "Couldn't establish MainFileID!");
655  return true;
656}
657
658// High-Level Operations
659
660bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
661  assert(hasDiagnostics() && "Diagnostics engine is not initialized!");
662  assert(!getFrontendOpts().ShowHelp && "Client must handle '-help'!");
663  assert(!getFrontendOpts().ShowVersion && "Client must handle '-version'!");
664
665  // FIXME: Take this as an argument, once all the APIs we used have moved to
666  // taking it as an input instead of hard-coding llvm::errs.
667  raw_ostream &OS = llvm::errs();
668
669  // Create the target instance.
670  setTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), &getTargetOpts()));
671  if (!hasTarget())
672    return false;
673
674  // Inform the target of the language options.
675  //
676  // FIXME: We shouldn't need to do this, the target should be immutable once
677  // created. This complexity should be lifted elsewhere.
678  getTarget().setForcedLangOptions(getLangOpts());
679
680  // rewriter project will change target built-in bool type from its default.
681  if (getFrontendOpts().ProgramAction == frontend::RewriteObjC)
682    getTarget().noSignedCharForObjCBool();
683
684  // Validate/process some options.
685  if (getHeaderSearchOpts().Verbose)
686    OS << "clang -cc1 version " CLANG_VERSION_STRING
687       << " based upon " << PACKAGE_STRING
688       << " default target " << llvm::sys::getDefaultTargetTriple() << "\n";
689
690  if (getFrontendOpts().ShowTimers)
691    createFrontendTimer();
692
693  if (getFrontendOpts().ShowStats)
694    llvm::EnableStatistics();
695
696  for (unsigned i = 0, e = getFrontendOpts().Inputs.size(); i != e; ++i) {
697    // Reset the ID tables if we are reusing the SourceManager.
698    if (hasSourceManager())
699      getSourceManager().clearIDTables();
700
701    if (Act.BeginSourceFile(*this, getFrontendOpts().Inputs[i])) {
702      Act.Execute();
703      Act.EndSourceFile();
704    }
705  }
706
707  // Notify the diagnostic client that all files were processed.
708  getDiagnostics().getClient()->finish();
709
710  if (getDiagnosticOpts().ShowCarets) {
711    // We can have multiple diagnostics sharing one diagnostic client.
712    // Get the total number of warnings/errors from the client.
713    unsigned NumWarnings = getDiagnostics().getClient()->getNumWarnings();
714    unsigned NumErrors = getDiagnostics().getClient()->getNumErrors();
715
716    if (NumWarnings)
717      OS << NumWarnings << " warning" << (NumWarnings == 1 ? "" : "s");
718    if (NumWarnings && NumErrors)
719      OS << " and ";
720    if (NumErrors)
721      OS << NumErrors << " error" << (NumErrors == 1 ? "" : "s");
722    if (NumWarnings || NumErrors)
723      OS << " generated.\n";
724  }
725
726  if (getFrontendOpts().ShowStats && hasFileManager()) {
727    getFileManager().PrintStats();
728    OS << "\n";
729  }
730
731  return !getDiagnostics().getClient()->getNumErrors();
732}
733
734/// \brief Determine the appropriate source input kind based on language
735/// options.
736static InputKind getSourceInputKindFromOptions(const LangOptions &LangOpts) {
737  if (LangOpts.OpenCL)
738    return IK_OpenCL;
739  if (LangOpts.CUDA)
740    return IK_CUDA;
741  if (LangOpts.ObjC1)
742    return LangOpts.CPlusPlus? IK_ObjCXX : IK_ObjC;
743  return LangOpts.CPlusPlus? IK_CXX : IK_C;
744}
745
746namespace {
747  struct CompileModuleMapData {
748    CompilerInstance &Instance;
749    GenerateModuleAction &CreateModuleAction;
750  };
751}
752
753/// \brief Helper function that executes the module-generating action under
754/// a crash recovery context.
755static void doCompileMapModule(void *UserData) {
756  CompileModuleMapData &Data
757    = *reinterpret_cast<CompileModuleMapData *>(UserData);
758  Data.Instance.ExecuteAction(Data.CreateModuleAction);
759}
760
761namespace {
762  /// \brief Function object that checks with the given macro definition should
763  /// be removed, because it is one of the ignored macros.
764  class RemoveIgnoredMacro {
765    const HeaderSearchOptions &HSOpts;
766
767  public:
768    explicit RemoveIgnoredMacro(const HeaderSearchOptions &HSOpts)
769      : HSOpts(HSOpts) { }
770
771    bool operator()(const std::pair<std::string, bool> &def) const {
772      StringRef MacroDef = def.first;
773      return HSOpts.ModulesIgnoreMacros.count(MacroDef.split('=').first) > 0;
774    }
775  };
776}
777
778/// \brief Compile a module file for the given module, using the options
779/// provided by the importing compiler instance.
780static void compileModule(CompilerInstance &ImportingInstance,
781                          SourceLocation ImportLoc,
782                          Module *Module,
783                          StringRef ModuleFileName) {
784  // FIXME: have LockFileManager return an error_code so that we can
785  // avoid the mkdir when the directory already exists.
786  StringRef Dir = llvm::sys::path::parent_path(ModuleFileName);
787  llvm::sys::fs::create_directories(Dir);
788
789  llvm::LockFileManager Locked(ModuleFileName);
790  switch (Locked) {
791  case llvm::LockFileManager::LFS_Error:
792    return;
793
794  case llvm::LockFileManager::LFS_Owned:
795    // We're responsible for building the module ourselves. Do so below.
796    break;
797
798  case llvm::LockFileManager::LFS_Shared:
799    // Someone else is responsible for building the module. Wait for them to
800    // finish.
801    Locked.waitForUnlock();
802    return;
803  }
804
805  ModuleMap &ModMap
806    = ImportingInstance.getPreprocessor().getHeaderSearchInfo().getModuleMap();
807
808  // Construct a compiler invocation for creating this module.
809  IntrusiveRefCntPtr<CompilerInvocation> Invocation
810    (new CompilerInvocation(ImportingInstance.getInvocation()));
811
812  PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
813
814  // For any options that aren't intended to affect how a module is built,
815  // reset them to their default values.
816  Invocation->getLangOpts()->resetNonModularOptions();
817  PPOpts.resetNonModularOptions();
818
819  // Remove any macro definitions that are explicitly ignored by the module.
820  // They aren't supposed to affect how the module is built anyway.
821  const HeaderSearchOptions &HSOpts = Invocation->getHeaderSearchOpts();
822  PPOpts.Macros.erase(std::remove_if(PPOpts.Macros.begin(), PPOpts.Macros.end(),
823                                     RemoveIgnoredMacro(HSOpts)),
824                      PPOpts.Macros.end());
825
826
827  // Note the name of the module we're building.
828  Invocation->getLangOpts()->CurrentModule = Module->getTopLevelModuleName();
829
830  // Make sure that the failed-module structure has been allocated in
831  // the importing instance, and propagate the pointer to the newly-created
832  // instance.
833  PreprocessorOptions &ImportingPPOpts
834    = ImportingInstance.getInvocation().getPreprocessorOpts();
835  if (!ImportingPPOpts.FailedModules)
836    ImportingPPOpts.FailedModules = new PreprocessorOptions::FailedModulesSet;
837  PPOpts.FailedModules = ImportingPPOpts.FailedModules;
838
839  // If there is a module map file, build the module using the module map.
840  // Set up the inputs/outputs so that we build the module from its umbrella
841  // header.
842  FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
843  FrontendOpts.OutputFile = ModuleFileName.str();
844  FrontendOpts.DisableFree = false;
845  FrontendOpts.GenerateGlobalModuleIndex = false;
846  FrontendOpts.Inputs.clear();
847  InputKind IK = getSourceInputKindFromOptions(*Invocation->getLangOpts());
848
849  // Get or create the module map that we'll use to build this module.
850  SmallString<128> TempModuleMapFileName;
851  if (const FileEntry *ModuleMapFile
852                                  = ModMap.getContainingModuleMapFile(Module)) {
853    // Use the module map where this module resides.
854    FrontendOpts.Inputs.push_back(FrontendInputFile(ModuleMapFile->getName(),
855                                                    IK));
856  } else {
857    // Create a temporary module map file.
858    int FD;
859    if (llvm::sys::fs::createTemporaryFile(Module->Name, "map", FD,
860                                           TempModuleMapFileName)) {
861      ImportingInstance.getDiagnostics().Report(diag::err_module_map_temp_file)
862        << TempModuleMapFileName;
863      return;
864    }
865    // Print the module map to this file.
866    llvm::raw_fd_ostream OS(FD, /*shouldClose=*/true);
867    Module->print(OS);
868    FrontendOpts.Inputs.push_back(
869      FrontendInputFile(TempModuleMapFileName.str().str(), IK));
870  }
871
872  // Don't free the remapped file buffers; they are owned by our caller.
873  PPOpts.RetainRemappedFileBuffers = true;
874
875  Invocation->getDiagnosticOpts().VerifyDiagnostics = 0;
876  assert(ImportingInstance.getInvocation().getModuleHash() ==
877         Invocation->getModuleHash() && "Module hash mismatch!");
878
879  // Construct a compiler instance that will be used to actually create the
880  // module.
881  CompilerInstance Instance;
882  Instance.setInvocation(&*Invocation);
883
884  Instance.createDiagnostics(new ForwardingDiagnosticConsumer(
885                                   ImportingInstance.getDiagnosticClient()),
886                             /*ShouldOwnClient=*/true);
887
888  // Note that this module is part of the module build stack, so that we
889  // can detect cycles in the module graph.
890  Instance.createFileManager(); // FIXME: Adopt file manager from importer?
891  Instance.createSourceManager(Instance.getFileManager());
892  SourceManager &SourceMgr = Instance.getSourceManager();
893  SourceMgr.setModuleBuildStack(
894    ImportingInstance.getSourceManager().getModuleBuildStack());
895  SourceMgr.pushModuleBuildStack(Module->getTopLevelModuleName(),
896    FullSourceLoc(ImportLoc, ImportingInstance.getSourceManager()));
897
898
899  // Construct a module-generating action.
900  GenerateModuleAction CreateModuleAction(Module->IsSystem);
901
902  // Execute the action to actually build the module in-place. Use a separate
903  // thread so that we get a stack large enough.
904  const unsigned ThreadStackSize = 8 << 20;
905  llvm::CrashRecoveryContext CRC;
906  CompileModuleMapData Data = { Instance, CreateModuleAction };
907  CRC.RunSafelyOnThread(&doCompileMapModule, &Data, ThreadStackSize);
908
909
910  // Delete the temporary module map file.
911  // FIXME: Even though we're executing under crash protection, it would still
912  // be nice to do this with RemoveFileOnSignal when we can. However, that
913  // doesn't make sense for all clients, so clean this up manually.
914  Instance.clearOutputFiles(/*EraseFiles=*/true);
915  if (!TempModuleMapFileName.empty())
916    llvm::sys::fs::remove(TempModuleMapFileName.str());
917
918  // We've rebuilt a module. If we're allowed to generate or update the global
919  // module index, record that fact in the importing compiler instance.
920  if (ImportingInstance.getFrontendOpts().GenerateGlobalModuleIndex) {
921    ImportingInstance.setBuildGlobalModuleIndex(true);
922  }
923}
924
925/// \brief Diagnose differences between the current definition of the given
926/// configuration macro and the definition provided on the command line.
927static void checkConfigMacro(Preprocessor &PP, StringRef ConfigMacro,
928                             Module *Mod, SourceLocation ImportLoc) {
929  IdentifierInfo *Id = PP.getIdentifierInfo(ConfigMacro);
930  SourceManager &SourceMgr = PP.getSourceManager();
931
932  // If this identifier has never had a macro definition, then it could
933  // not have changed.
934  if (!Id->hadMacroDefinition())
935    return;
936
937  // If this identifier does not currently have a macro definition,
938  // check whether it had one on the command line.
939  if (!Id->hasMacroDefinition()) {
940    MacroDirective::DefInfo LatestDef =
941        PP.getMacroDirectiveHistory(Id)->getDefinition();
942    for (MacroDirective::DefInfo Def = LatestDef; Def;
943           Def = Def.getPreviousDefinition()) {
944      FileID FID = SourceMgr.getFileID(Def.getLocation());
945      if (FID.isInvalid())
946        continue;
947
948      // We only care about the predefines buffer.
949      if (FID != PP.getPredefinesFileID())
950        continue;
951
952      // This macro was defined on the command line, then #undef'd later.
953      // Complain.
954      PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
955        << true << ConfigMacro << Mod->getFullModuleName();
956      if (LatestDef.isUndefined())
957        PP.Diag(LatestDef.getUndefLocation(), diag::note_module_def_undef_here)
958          << true;
959      return;
960    }
961
962    // Okay: no definition in the predefines buffer.
963    return;
964  }
965
966  // This identifier has a macro definition. Check whether we had a definition
967  // on the command line.
968  MacroDirective::DefInfo LatestDef =
969      PP.getMacroDirectiveHistory(Id)->getDefinition();
970  MacroDirective::DefInfo PredefinedDef;
971  for (MacroDirective::DefInfo Def = LatestDef; Def;
972         Def = Def.getPreviousDefinition()) {
973    FileID FID = SourceMgr.getFileID(Def.getLocation());
974    if (FID.isInvalid())
975      continue;
976
977    // We only care about the predefines buffer.
978    if (FID != PP.getPredefinesFileID())
979      continue;
980
981    PredefinedDef = Def;
982    break;
983  }
984
985  // If there was no definition for this macro in the predefines buffer,
986  // complain.
987  if (!PredefinedDef ||
988      (!PredefinedDef.getLocation().isValid() &&
989       PredefinedDef.getUndefLocation().isValid())) {
990    PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
991      << false << ConfigMacro << Mod->getFullModuleName();
992    PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
993      << false;
994    return;
995  }
996
997  // If the current macro definition is the same as the predefined macro
998  // definition, it's okay.
999  if (LatestDef.getMacroInfo() == PredefinedDef.getMacroInfo() ||
1000      LatestDef.getMacroInfo()->isIdenticalTo(*PredefinedDef.getMacroInfo(),PP,
1001                                              /*Syntactically=*/true))
1002    return;
1003
1004  // The macro definitions differ.
1005  PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
1006    << false << ConfigMacro << Mod->getFullModuleName();
1007  PP.Diag(LatestDef.getLocation(), diag::note_module_def_undef_here)
1008    << false;
1009}
1010
1011/// \brief Write a new timestamp file with the given path.
1012static void writeTimestampFile(StringRef TimestampFile) {
1013  std::string ErrorInfo;
1014  llvm::raw_fd_ostream Out(TimestampFile.str().c_str(), ErrorInfo,
1015                           llvm::raw_fd_ostream::F_Binary);
1016}
1017
1018/// \brief Prune the module cache of modules that haven't been accessed in
1019/// a long time.
1020static void pruneModuleCache(const HeaderSearchOptions &HSOpts) {
1021  struct stat StatBuf;
1022  llvm::SmallString<128> TimestampFile;
1023  TimestampFile = HSOpts.ModuleCachePath;
1024  llvm::sys::path::append(TimestampFile, "modules.timestamp");
1025
1026  // Try to stat() the timestamp file.
1027  if (::stat(TimestampFile.c_str(), &StatBuf)) {
1028    // If the timestamp file wasn't there, create one now.
1029    if (errno == ENOENT) {
1030      writeTimestampFile(TimestampFile);
1031    }
1032    return;
1033  }
1034
1035  // Check whether the time stamp is older than our pruning interval.
1036  // If not, do nothing.
1037  time_t TimeStampModTime = StatBuf.st_mtime;
1038  time_t CurrentTime = time(0);
1039  if (CurrentTime - TimeStampModTime <= time_t(HSOpts.ModuleCachePruneInterval))
1040    return;
1041
1042  // Write a new timestamp file so that nobody else attempts to prune.
1043  // There is a benign race condition here, if two Clang instances happen to
1044  // notice at the same time that the timestamp is out-of-date.
1045  writeTimestampFile(TimestampFile);
1046
1047  // Walk the entire module cache, looking for unused module files and module
1048  // indices.
1049  llvm::error_code EC;
1050  SmallString<128> ModuleCachePathNative;
1051  llvm::sys::path::native(HSOpts.ModuleCachePath, ModuleCachePathNative);
1052  for (llvm::sys::fs::directory_iterator
1053         Dir(ModuleCachePathNative.str(), EC), DirEnd;
1054       Dir != DirEnd && !EC; Dir.increment(EC)) {
1055    // If we don't have a directory, there's nothing to look into.
1056    bool IsDirectory;
1057    if (llvm::sys::fs::is_directory(Dir->path(), IsDirectory) || !IsDirectory)
1058      continue;
1059
1060    // Walk all of the files within this directory.
1061    bool RemovedAllFiles = true;
1062    for (llvm::sys::fs::directory_iterator File(Dir->path(), EC), FileEnd;
1063         File != FileEnd && !EC; File.increment(EC)) {
1064      // We only care about module and global module index files.
1065      if (llvm::sys::path::extension(File->path()) != ".pcm" &&
1066          llvm::sys::path::filename(File->path()) != "modules.idx") {
1067        RemovedAllFiles = false;
1068        continue;
1069      }
1070
1071      // Look at this file. If we can't stat it, there's nothing interesting
1072      // there.
1073      if (::stat(File->path().c_str(), &StatBuf)) {
1074        RemovedAllFiles = false;
1075        continue;
1076      }
1077
1078      // If the file has been used recently enough, leave it there.
1079      time_t FileAccessTime = StatBuf.st_atime;
1080      if (CurrentTime - FileAccessTime <=
1081              time_t(HSOpts.ModuleCachePruneAfter)) {
1082        RemovedAllFiles = false;
1083        continue;
1084      }
1085
1086      // Remove the file.
1087      bool Existed;
1088      if (llvm::sys::fs::remove(File->path(), Existed) || !Existed) {
1089        RemovedAllFiles = false;
1090      }
1091    }
1092
1093    // If we removed all of the files in the directory, remove the directory
1094    // itself.
1095    if (RemovedAllFiles) {
1096      bool Existed;
1097      llvm::sys::fs::remove(Dir->path(), Existed);
1098    }
1099  }
1100}
1101
1102ModuleLoadResult
1103CompilerInstance::loadModule(SourceLocation ImportLoc,
1104                             ModuleIdPath Path,
1105                             Module::NameVisibilityKind Visibility,
1106                             bool IsInclusionDirective) {
1107  // If we've already handled this import, just return the cached result.
1108  // This one-element cache is important to eliminate redundant diagnostics
1109  // when both the preprocessor and parser see the same import declaration.
1110  if (!ImportLoc.isInvalid() && LastModuleImportLoc == ImportLoc) {
1111    // Make the named module visible.
1112    if (LastModuleImportResult)
1113      ModuleManager->makeModuleVisible(LastModuleImportResult, Visibility,
1114                                       ImportLoc, /*Complain=*/false);
1115    return LastModuleImportResult;
1116  }
1117
1118  // Determine what file we're searching from.
1119  StringRef ModuleName = Path[0].first->getName();
1120  SourceLocation ModuleNameLoc = Path[0].second;
1121
1122  clang::Module *Module = 0;
1123
1124  // If we don't already have information on this module, load the module now.
1125  llvm::DenseMap<const IdentifierInfo *, clang::Module *>::iterator Known
1126    = KnownModules.find(Path[0].first);
1127  if (Known != KnownModules.end()) {
1128    // Retrieve the cached top-level module.
1129    Module = Known->second;
1130  } else if (ModuleName == getLangOpts().CurrentModule) {
1131    // This is the module we're building.
1132    Module = PP->getHeaderSearchInfo().getModuleMap().findModule(ModuleName);
1133    Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1134  } else {
1135    // Search for a module with the given name.
1136    Module = PP->getHeaderSearchInfo().lookupModule(ModuleName);
1137    std::string ModuleFileName;
1138    if (Module) {
1139      ModuleFileName = PP->getHeaderSearchInfo().getModuleFileName(Module);
1140    } else
1141      ModuleFileName = PP->getHeaderSearchInfo().getModuleFileName(ModuleName);
1142
1143    // If we don't already have an ASTReader, create one now.
1144    if (!ModuleManager) {
1145      if (!hasASTContext())
1146        createASTContext();
1147
1148      // If we're not recursively building a module, check whether we
1149      // need to prune the module cache.
1150      if (getSourceManager().getModuleBuildStack().empty() &&
1151          getHeaderSearchOpts().ModuleCachePruneInterval > 0 &&
1152          getHeaderSearchOpts().ModuleCachePruneAfter > 0) {
1153        pruneModuleCache(getHeaderSearchOpts());
1154      }
1155
1156      std::string Sysroot = getHeaderSearchOpts().Sysroot;
1157      const PreprocessorOptions &PPOpts = getPreprocessorOpts();
1158      ModuleManager = new ASTReader(getPreprocessor(), *Context,
1159                                    Sysroot.empty() ? "" : Sysroot.c_str(),
1160                                    PPOpts.DisablePCHValidation,
1161                                    /*AllowASTWithCompilerErrors=*/false,
1162                                    getFrontendOpts().UseGlobalModuleIndex);
1163      if (hasASTConsumer()) {
1164        ModuleManager->setDeserializationListener(
1165          getASTConsumer().GetASTDeserializationListener());
1166        getASTContext().setASTMutationListener(
1167          getASTConsumer().GetASTMutationListener());
1168      }
1169      OwningPtr<ExternalASTSource> Source;
1170      Source.reset(ModuleManager);
1171      getASTContext().setExternalSource(Source);
1172      if (hasSema())
1173        ModuleManager->InitializeSema(getSema());
1174      if (hasASTConsumer())
1175        ModuleManager->StartTranslationUnit(&getASTConsumer());
1176    }
1177
1178    // Try to load the module file.
1179    unsigned ARRFlags = ASTReader::ARR_OutOfDate | ASTReader::ARR_Missing;
1180    switch (ModuleManager->ReadAST(ModuleFileName, serialization::MK_Module,
1181                                   ImportLoc, ARRFlags)) {
1182    case ASTReader::Success:
1183      break;
1184
1185    case ASTReader::OutOfDate: {
1186      // The module file is out-of-date. Remove it, then rebuild it.
1187      bool Existed;
1188      llvm::sys::fs::remove(ModuleFileName, Existed);
1189    }
1190    // Fall through to build the module again.
1191
1192    case ASTReader::Missing: {
1193      // The module file is (now) missing. Build it.
1194
1195      // If we don't have a module, we don't know how to build the module file.
1196      // Complain and return.
1197      if (!Module) {
1198        getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_found)
1199          << ModuleName
1200          << SourceRange(ImportLoc, ModuleNameLoc);
1201        ModuleBuildFailed = true;
1202        return ModuleLoadResult();
1203      }
1204
1205      // Check whether there is a cycle in the module graph.
1206      ModuleBuildStack ModPath = getSourceManager().getModuleBuildStack();
1207      ModuleBuildStack::iterator Pos = ModPath.begin(), PosEnd = ModPath.end();
1208      for (; Pos != PosEnd; ++Pos) {
1209        if (Pos->first == ModuleName)
1210          break;
1211      }
1212
1213      if (Pos != PosEnd) {
1214        SmallString<256> CyclePath;
1215        for (; Pos != PosEnd; ++Pos) {
1216          CyclePath += Pos->first;
1217          CyclePath += " -> ";
1218        }
1219        CyclePath += ModuleName;
1220
1221        getDiagnostics().Report(ModuleNameLoc, diag::err_module_cycle)
1222          << ModuleName << CyclePath;
1223        return ModuleLoadResult();
1224      }
1225
1226      // Check whether we have already attempted to build this module (but
1227      // failed).
1228      if (getPreprocessorOpts().FailedModules &&
1229          getPreprocessorOpts().FailedModules->hasAlreadyFailed(ModuleName)) {
1230        getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_built)
1231          << ModuleName
1232          << SourceRange(ImportLoc, ModuleNameLoc);
1233        ModuleBuildFailed = true;
1234        return ModuleLoadResult();
1235      }
1236
1237      // Try to compile the module.
1238      compileModule(*this, ModuleNameLoc, Module, ModuleFileName);
1239
1240      // Try to read the module file, now that we've compiled it.
1241      ASTReader::ASTReadResult ReadResult
1242        = ModuleManager->ReadAST(ModuleFileName,
1243                                 serialization::MK_Module, ImportLoc,
1244                                 ASTReader::ARR_Missing);
1245      if (ReadResult != ASTReader::Success) {
1246        if (ReadResult == ASTReader::Missing) {
1247          getDiagnostics().Report(ModuleNameLoc,
1248                                  Module? diag::err_module_not_built
1249                                        : diag::err_module_not_found)
1250            << ModuleName
1251            << SourceRange(ImportLoc, ModuleNameLoc);
1252        }
1253
1254        if (getPreprocessorOpts().FailedModules)
1255          getPreprocessorOpts().FailedModules->addFailed(ModuleName);
1256        KnownModules[Path[0].first] = 0;
1257        ModuleBuildFailed = true;
1258        return ModuleLoadResult();
1259      }
1260
1261      // Okay, we've rebuilt and now loaded the module.
1262      break;
1263    }
1264
1265    case ASTReader::VersionMismatch:
1266    case ASTReader::ConfigurationMismatch:
1267    case ASTReader::HadErrors:
1268      ModuleLoader::HadFatalFailure = true;
1269      // FIXME: The ASTReader will already have complained, but can we showhorn
1270      // that diagnostic information into a more useful form?
1271      KnownModules[Path[0].first] = 0;
1272      return ModuleLoadResult();
1273
1274    case ASTReader::Failure:
1275      ModuleLoader::HadFatalFailure = true;
1276      // Already complained, but note now that we failed.
1277      KnownModules[Path[0].first] = 0;
1278      ModuleBuildFailed = true;
1279      return ModuleLoadResult();
1280    }
1281
1282    if (!Module) {
1283      // If we loaded the module directly, without finding a module map first,
1284      // we'll have loaded the module's information from the module itself.
1285      Module = PP->getHeaderSearchInfo().getModuleMap()
1286                 .findModule((Path[0].first->getName()));
1287    }
1288
1289    // Cache the result of this top-level module lookup for later.
1290    Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1291  }
1292
1293  // If we never found the module, fail.
1294  if (!Module)
1295    return ModuleLoadResult();
1296
1297  // Verify that the rest of the module path actually corresponds to
1298  // a submodule.
1299  if (Path.size() > 1) {
1300    for (unsigned I = 1, N = Path.size(); I != N; ++I) {
1301      StringRef Name = Path[I].first->getName();
1302      clang::Module *Sub = Module->findSubmodule(Name);
1303
1304      if (!Sub) {
1305        // Attempt to perform typo correction to find a module name that works.
1306        SmallVector<StringRef, 2> Best;
1307        unsigned BestEditDistance = (std::numeric_limits<unsigned>::max)();
1308
1309        for (clang::Module::submodule_iterator J = Module->submodule_begin(),
1310                                            JEnd = Module->submodule_end();
1311             J != JEnd; ++J) {
1312          unsigned ED = Name.edit_distance((*J)->Name,
1313                                           /*AllowReplacements=*/true,
1314                                           BestEditDistance);
1315          if (ED <= BestEditDistance) {
1316            if (ED < BestEditDistance) {
1317              Best.clear();
1318              BestEditDistance = ED;
1319            }
1320
1321            Best.push_back((*J)->Name);
1322          }
1323        }
1324
1325        // If there was a clear winner, user it.
1326        if (Best.size() == 1) {
1327          getDiagnostics().Report(Path[I].second,
1328                                  diag::err_no_submodule_suggest)
1329            << Path[I].first << Module->getFullModuleName() << Best[0]
1330            << SourceRange(Path[0].second, Path[I-1].second)
1331            << FixItHint::CreateReplacement(SourceRange(Path[I].second),
1332                                            Best[0]);
1333
1334          Sub = Module->findSubmodule(Best[0]);
1335        }
1336      }
1337
1338      if (!Sub) {
1339        // No submodule by this name. Complain, and don't look for further
1340        // submodules.
1341        getDiagnostics().Report(Path[I].second, diag::err_no_submodule)
1342          << Path[I].first << Module->getFullModuleName()
1343          << SourceRange(Path[0].second, Path[I-1].second);
1344        break;
1345      }
1346
1347      Module = Sub;
1348    }
1349  }
1350
1351  // Make the named module visible, if it's not already part of the module
1352  // we are parsing.
1353  if (ModuleName != getLangOpts().CurrentModule) {
1354    if (!Module->IsFromModuleFile) {
1355      // We have an umbrella header or directory that doesn't actually include
1356      // all of the headers within the directory it covers. Complain about
1357      // this missing submodule and recover by forgetting that we ever saw
1358      // this submodule.
1359      // FIXME: Should we detect this at module load time? It seems fairly
1360      // expensive (and rare).
1361      getDiagnostics().Report(ImportLoc, diag::warn_missing_submodule)
1362        << Module->getFullModuleName()
1363        << SourceRange(Path.front().second, Path.back().second);
1364
1365      return ModuleLoadResult(0, true);
1366    }
1367
1368    // Check whether this module is available.
1369    StringRef Feature;
1370    if (!Module->isAvailable(getLangOpts(), getTarget(), Feature)) {
1371      getDiagnostics().Report(ImportLoc, diag::err_module_unavailable)
1372        << Module->getFullModuleName()
1373        << Feature
1374        << SourceRange(Path.front().second, Path.back().second);
1375      LastModuleImportLoc = ImportLoc;
1376      LastModuleImportResult = ModuleLoadResult();
1377      return ModuleLoadResult();
1378    }
1379
1380    ModuleManager->makeModuleVisible(Module, Visibility, ImportLoc,
1381                                     /*Complain=*/true);
1382  }
1383
1384  // Check for any configuration macros that have changed.
1385  clang::Module *TopModule = Module->getTopLevelModule();
1386  for (unsigned I = 0, N = TopModule->ConfigMacros.size(); I != N; ++I) {
1387    checkConfigMacro(getPreprocessor(), TopModule->ConfigMacros[I],
1388                     Module, ImportLoc);
1389  }
1390
1391  // If this module import was due to an inclusion directive, create an
1392  // implicit import declaration to capture it in the AST.
1393  if (IsInclusionDirective && hasASTContext()) {
1394    TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl();
1395    ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU,
1396                                                     ImportLoc, Module,
1397                                                     Path.back().second);
1398    TU->addDecl(ImportD);
1399    if (Consumer)
1400      Consumer->HandleImplicitImportDecl(ImportD);
1401  }
1402
1403  LastModuleImportLoc = ImportLoc;
1404  LastModuleImportResult = ModuleLoadResult(Module, false);
1405  return LastModuleImportResult;
1406}
1407
1408void CompilerInstance::makeModuleVisible(Module *Mod,
1409                                         Module::NameVisibilityKind Visibility,
1410                                         SourceLocation ImportLoc,
1411                                         bool Complain){
1412  ModuleManager->makeModuleVisible(Mod, Visibility, ImportLoc, Complain);
1413}
1414
1415